Accretional remanence of magnetized dust in the solar nebula

Anticipating the results from the Rosetta magnetometer experiment, we prese nt a theoretical study concerning the possible origin of a cometary magneti c field. Assuming the existence of a permanently magnetized iron dust fract ion in the primordial solar nebula, we use a numerical model to investigate the outcome of a dust aggregation process involving both magnetic and nonm agnetic preplanetary grains. The growing dust aggregates of low fractal dim ension and sizes on the order of 1 mu m conserve magnetization to a large e xtent and could thus serve as building material for larger permanently magn etized celestial objects. A special focus is put on deriving numerical para meters for magnetic dust aggregates that can be used in subsequent numerica l studies. On the basis of our results, we outline possible future lines of study involving the optical and mechanical properties of magnetized dust, (C) 2000 Academic Press.